How the best scenes in the 'Game of Thrones' season 6 finale came to life

During the "Game of Thrones" season six finale, Cersei let loose a batch of wildfire and blew up the Great Sept of Baelor in King's Landing.

It was one of the most dramatic and thrilling moments in the show's history. And of course, a lot of work went into it making it look so cool.

Rising Sun Pictures, one of the visual effects companies that works on "Game of Thrones," put out a video compiling their work on the season finale. It reveals some surprising things. While the King's Landing scenes are mostly shot on location in Croatia, green screens add more details to the world of Westeros.

While it looked like there was a huge army outside the Sept, much of it was actually CGI: